Timing motor with resonant members

ABSTRACT

A D.C. energized timing motor with one or more resonators, having a plurality of coordinately moving arms, all magnetically coupled to the rim of a rotor and in which the motion of the resonator arms drives the rotor with driving force being applied in each quadrant of the rotor without retarding torque and in which the magnetic coupling between rotor and resonator is at no time released.

United States Patent Allison [54] TIMING MOTOR WITH RESONANT MEMBERS [72] Inventor: William W. Allison, Melville, NY.

[73] Assignee: Armec Corporation, Huntington Station,

22 Filed: Aug. 7, 1970 211 App1.No.: 62,104

[52] U.S. Cl. ..318/128, 310/22, 58/23 [51 1 Int. Cl. ..HOZR 33/00 [58] Field ofSearch ..310/20,2l,22, 25, 29; 318/128-133, 134; 58/23, 230, 116; 74/1.5;

' 331/ll6,116M

[ I References Cited UNITED STATES PATENTS v 3,518,464 6/1970 Kawakarni a a1. ..310/22 1 June 20, 1972 3,474,270 10/1969 Dietsch ..310/29 X 3,150,337 9/1964 Allison ....331/l16 X 3,519,856 7/1970 Cliflord ..3l0/25 X 3,522,500 8/1970 Clifiord ..3l0/25 X Primary Examiner-D. F. Duggan Attorney-James A. Eisenman and Robert R. Strack [511 I ABSTRACT A DC. energized timing motor with one or more resonators, having a plurality of coordinately moving arms, all magnetically coupled to the rim of a rotor and in which the motion of the resonator arms drives the rotor with'driving force being applied in each quadrant of the rotor without retarding torque and in which the magnetic coupling between rotor and resonator is at no time released.

19 Chung, 7D rlwlng Figures AMP2 (PICK-UP a omve) PATENTEDJUH 2 0 I972 SHEET 1 or 5 AMP 2 (DRIVE ONLY) (PICK-UP a DRIVE) FIG, I

N O Rmm OL TL A W M m L W ATTORNEYS.

PATENTEDJIIII20 I972 SHEET 20F 3 Nb llc Hd m I, I6 I F/GI 24 I2 lob l4 I5 14 12c d I20 I4 I5 k I I fT n I I l :2l0 I00 220 I 22 He IO H lid L-1 I I I RESONATOR I2 r RESONATOR ll 2lo 2|c/*2T-- 2m l W |9d PICK UP DRIVE I PICK UP I DRIVE 2 Q AMP2 q, SHIFT 2 AMP l SHIFT l V, INVENTOR.

I WILLIAM w. ALLISON 2 v 7 BY 2 W ATTORNEYS P'A'TE'N'TEBaunzo I972 3,671,825

sum 3 or 2 INVENTOR.

WlLLIAM W. ALLISON BY M d m ATTORNEYS.

TIMING MOTOR WI'I'II RESONANT MEMBERS BACKGROUND OF THE INVENTION The invention relates to timing motors and, in particular, to DC. energized timing motors incorporating their own frequency reference in the form of a multi-armed resonator coupled to the rotor.

Resonator-controlled timing motors have been developed in which the resonator is mechanically coupled to the rotor, in which the resonator is magnetically coupled to the rotor, and in which the resonator controls rotor motion through intervening electromagnetic means. In most such designs, there are load effects on the resonator which adversely affect its efficiency as a timekeeper, or which adversely affect the torque, or both. The present invention isconcemed with improving all phases of motor operation in which resonators are part of the motor assembly.

SUMMARY OF THE INVENTION In accordance with the invention, there is provided a resonator, preferably in the form of a cruciform plate, in which the arms resonate in a coordinate fashion out of the common plane. Each arm of the resonator carries a toothed magnet in which the north and south poles define a channel configuration opening in a direction perpendicular to the plane of the rotor to engage a magnetic rim of sinuous contour on the rotor. The resonator is excited by a suitable electromagnetic drive system, and when vibrating there is substantially no net axial thrust or reaction between the resonator and the rotor. Also, a torque coupling to the rotor is maintained at a plurality of circumferential points at all times, and these points can be disposed in all quadrants. In this fashion, the rotor can be driven with torque distributed about its entire circumference. Furthermore, the load on the resonator is balanced, both in the plane of the resonator and in directions perpendicular to the plane thereof. The invention thus provides for strong coupling between the rotor and the resonator without adversely affecting its performance as a timekeeper.

Two resonators, one or both of which can be driven, can be coupled to the rotor through a common or through a second sinuous rim, with appropriate angular phase shift or displacement to further distribute loads and increase torque. In one preferred arrangement of the invention, all resonant action can be consolidated in a single plate unit having, for example, eight arms which operate as two resonators which can be coordinately coupled to a common rotor through a single appropriately geometrically contoured rim.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an exploded view in perspective of a resonatordriven. D.C. energized timing motor and oscillator circuit;

FIG. 2 is an enlarged view in transverse section of the motor of FIG. I as assembled but showing an alternative oscillator circuit;

FIG. 2A is a further enlarged, fragmentary, developed view of the dual rim pattern of the motor of FIG. I, showing the interaction of the resonators therewith in each of the four quadrants;

FIG. 3 is an exploded view in perspective of another modification of the invention:

FIG. 4 is an exploded view of yet another modification of the invention;

FIG. 5 is a view in transverse section of the motor of FIG. 4 as assembled; and

FIG. 6 is a plan view of another modification.

Referring to FIGS. 1 and 2, the invention is illustrated as embodied in a D.C. timing motor including a rotor 10, a first mechanical resonator 11 on one side of the rotor and a second resonator 12 on the other side, together with circuit means indicated generally by the numeral 13 for exciting the resonators into resonance, which in turn actuates the rotor. The two resonators preferably take the'form of a cross or cruciform in accordance with the applicant's U.S. Pat. No. 3,150,337, with each including a central nodal mounting preferably coaxial with the rotor. Each of the four arms of the two resonators carries magnetic pole assemblies 11a, b, c and d and 12a, b, c and d, all being substantially identical. Each resonator pole assembly subtends an arc of slightly less than 90 and each has a U-shaped or channel configuration and includes a plurality of pairs of radially spaced poles 14 carrying intumed tip portions 15 at their upper ends. Each pole piece can be formed of a permanently magnetizable material or can include in its structure a permanently magnetizable link to polarizethe opposing pole tips 15 north and south.

Carried by the rotor 10 are a pair of circular rim portions in the form of sinuous strips 10a and 10b of magnetic material, received in the channels of the pole pieces of the resonators, with the rim 10a being received in the pole pieces 110, b, c and d, and the rim 10b received in the pole pieces [20, b, c and d. The sinuous pattern of the rims are constituted of a series of successive sine wave (or variants thereof) patterns, with the length of each sine wave pattern corresponding to the distance between pole tips 15 as measured circumferentially. Thus, the sinuous rim is gripped transversely with respect to the direction of resonator motion, and it is gripped in each quadrant symmetrically about the circumference of the rotor. If desired, it can be gripped as much as once for each sine wave pattern in the rim or can be gripped at a lesser number of points. In vibration, adjacent arms of a crucifonn resonator move in opposite directions at any given moment, and accordingly the pole assemblies or, more particularly, the pole tips 15, of adjacent arms of each resonatorare displaced 180 along the sine wave pattern, as best seen in FIG. 2A, in which the normal plane of the resonator is identified by the numeral 16, and the limits of travel or excursion of the resonator are indicated by the numerals l7 and 18. As the resonator anns vibrate up and down, the rotor will be moved along in synchronism therewith, with each arm and each pole pair of each arm imparting equal driving forces at all points in which the pole tips 15 are disposed in the sloping areas of the sine wave. The cruciform resonators are formed in accordance with the invention in a geometry which affords large excursions of the arm tips without metal deformation (or oilcanning) in the central areas by imparting an outward taper to each of the arms so that the deflection or bending of the arms occurs progressively outwardly. Other controls of the bending of the arms can be effected by other techniques, such as r the resonator do not cause a reaction with the rim which would create an apparent change in the spring constant of the resonator which, by definition, would change its timekeeping. As will be pointed out below, in connection with the description of the embodiment illustrated in FIG. 3, it is preferable to include this rim thickness distortion only in the cases in which the resonator is driven externally, as in the case of the motor of FIGS. I and 2.

The lower sinuous rim track 10b constitutes a mirrorimage of the track 100, but shifted of one sine wave pattern circumferentially. This 90-shift of sine wave tracks can also be achieved by turning one of the resonators relative to the other to shift the arms an equivalent amount on the sine wave track. The resonators are, in the illustrated arrangement, also shifted approximately 45 around the perimeter of the rotor in order to isolate their respective drive coils (described below) to avoid undesired magnetic coupling of flux.

In addition to a small angular shift of the sine wave tracks 10a and 101: (or of the resonators 11 and 12), the poles 15 of the respective arms of each resonator are shifted along the sine wave pattern, i.e., the poles 15 associated with the arm Ila are displaced 180 from the poles 15 of the arm 11b, and so on in each successive arm 11c and 11d. Thus, the poles of the arms 11a and 110 are in phase and the poles of the arms 11b and 11d are in phase but offset 180 from the other pair. This displacement accommodates the fact that adjacent arms move in opposite directions. Furthermore, to accommodate the 90-shift of the sinuous track (or of the resonator), a phase shift is imparted between the drive systems for the two resonators, indicated by means of circuitry described below. In this fashion, the resonator-rotor coupling at all times includes sloping portions of the sinuous track. When one resonator has carried two of its poles 15 to the crests and two to the troughs of the sine wave pattern (as shown in the case of the sinuous rim b of FIG. 2A), all four poles of the other resonator will be at the points of maximum slope (rim 10a At all other times, all poles will be disposed on the sloping portions of the sinuous track but not on the portions of maximum slope. As a result, smooth and balanced torque is applied.

In addition, due to the flux coupling across the thickness of the track from one pole tip 15 facing one side of the track and through the thickness of the track to the radially opposed pole 15 on the opposite side, the resonator is freed of magnetic bias which would stress the vibrating arms of the resonator in a manner which would significantly affect the time-keeping function. This is so even though strong magnetic coupling is achieved at many points. No matter how strong the coupling, there is at no time imposed on any vibrating arm a longitudinal force which would change the spring constant of the arm. Also, any change in coupling due to a change in the phase of resonator relative to the rotor, which is to say any change in which the pole tips 15 are moved toward or away from precise alignment with the track will not stress the arms longitudinally. The interchange of energy between the resonators and the rotor (in either direction) is brought about by such phase shifts and they occur as function of very small changes in rotor speed, as described in greater detail below.

It is desirable to avoid the need for shifting energy from one arm of a given resonator to another, i.e. feeding driving energy into the resonator through one arm and extracting stored energy from the resonator through another arm. Accordingly, the loads of the rotor on the resonators are isolated from the resonator action per se by driving each arm of each resonator. For this purpose, in the illustrated arrangement, an elec tromagnetic drive system is employed in which coils 19a -d drive the ends of the arms 11a -d of the resonator 11 through permanent magnets 20a d respectively, which are affixed to the arms. In the case of the resonator 12, four coils 21a -d are provided, together with four resonator-supported permanent magnets 22a -d respectively.

Because the resonators 11 and 12 are operated at the same frequency, the drive circuits are linked either by a common pickup and phase shifter (FIG. 1) or by two pickups and a phase lock network (FIG. 2). Referring to FIG. 1, a drive system for the resonators is shown in which drive forces are imparted to all arms of all of the two resonators 11 and 12 through the coils 19a -d and 21a d respectively. While drive current is passed through all eight coils in a desired phase relation, pickup signals are derived from only one set of coils, in this case coils 19a -d, which therefore perform dual functions. To this end, the coils 19a d are series-connected in a bridge circuit oscillator configuration to the collector of a transistor 24, the emitter of which is connected to ground through a resistor 25 and a balance coil 26. The base electrode is connected to a positive D.C. source through a resistor 27. The collector is also connected through a capacitor 28 and resistors 29 and 30 to the base of a second transistor 31, the emitter of which is connected to ground and the collector of which is connected to the resistor 27 and, through a feedback path, to the base of the transistor 24. The circuit as described constitutes an amplifier and oscillator for supplying drive current to the coils 19a -d.

The coils 210 -d are connected in series to a second amplifier circuit including a transistor 32 and an emitter resistor 33 connected to the D.C. source. The two amplifiers are connected by a phase shift circuit including a resistor 34 and capacitors 35 and 36, with the signal from the first amplifier being connected to the phase shifter through the resistor 37 and through the capacitor 28 and resistor 29.

Thus, there is provided an oscillator circuit including two driven resonators, one directly driven from its own pickup signal and the other driven from the same signal with a phase shift. This achieves the necessary out-of-phase operation of the two resonators, all as described above in connection with FIG. 2A. The operation of the bridge oscillator circuit is such that when a signal is applied to the base of the transistor24, current flows through the four coils 19a -d with the same current flowing through the resistor 25 and the balance coil 26. Due to current alone, voltages appear on the collector and in the balance coil 26. The balance coil is made equal in inductance and resistance to the sum of all four coils 19a -d, thus resulting in a voltage on the collector which is equal and opposite to the voltage on the balance coil. The condenser 28 in the collector circuit is relatively large to present a low impedance, and the voltage appearing at the resistor 30 due to current in the four coils 1911 d is zero. Assuming now that the resonator arms are in motion, an additive .voltage will be generated in all of the coils 19a -d. This voltage is divided by the resistance ratio of the resistors 29 and 30, and is amplified by the transistor 31 and fed back directly to the base of the transistor 24, where it appears as an amplified pickup voltage so that current is successively turned on and off to drive the resonator. Thus, the bridge balances out voltage on the coils due to current and leaves untouched the voltage generated by the resonance of the resonator 11.

The resonator 12 which has no pickup is driven by the amplifier transistor 32 as a result of the pickup voltage from the resonator 11 appearing at the resistor 30. This voltage, however, is fed into the stage or portion of the phase shifter network including resistor 34 and capacitor 35 where it is amplified to drive all four arms of the resonator 12. The first stage of the phase shift is less than 90 and the balance of the phase shift, making a total of 90, is derived from the capacitor 36 in the power output side of the transistor 32.

The circuitry shown in FIG. 2 differs from the circuitry shown in FIG. 1 in that pickup signals are derived from both resonators and both have their own associated power amplifiers. The desired 90 phase shift between the two drives is derived from a phase lock circuit constituted of two 90 phase shifters 38 and 39, one leading and one lagging, in the respective circuits to the resonators 11 and 12. Amplifier circuits identified generally by the numerals 40 and 41 are also provided for the resonators 11 and 12 respectively. The amplifiers are substantially identical for each resonator and therefore only the amplifier used for the resonator 11 will be described in detail. Two of the coils 19a and c constitute the pickup means and are connected in series to the base of a first voltage amplifier stage including a transistor 42 feeding into a second and power amplifier stage including a transistor 43, the output of which is connected to the series-connected drive coils 19b and d.

The output of the phase shifter network 38, including a resistor and capacitor, is connected to the series-connected pickup coils 21a and c of the resonator 12, which feed a duplicate voltage amplifier stage, the output of which is passed through the second phase shifter 39. The output of the second phase shifter 39 is connected back to the pickup coils 19a and c of the resonator 11. The phase shift function also involves the resistors 44 and 45 connected in the first amplifier stage 42. Their ratio represents the gain of that stage, but they also serve as a phase inverter for feeding the phase shifter network 38. In operation, therefore, the phase shifter network 38 furnishes a 90 lagging signal which is fed into the pickup circuit of the resonator 12, and the signal generated by the phase shifter network 39 of the resonator 12 has a 90 leading phase shift which is fed back to the pickup circuit of the resonator 11. Thus, the two electro-mechanical oscillators are lock in a 90 phase relationship.

To insure stability in the phase-lock loop, the loop gain must be less than 1. To insure that the operating frequency of both resonators is not affected by changes in circuit constants, the input to each amplifier from the phase shifter of the other must be small compared to the output of each pickup. Both conditions are satisfied by attenuating the output of each phase shifter by a factor of approximately 10, or as required by the stability of circuit parameters, using attenuator circuits 38a and 39a.

The circuitry of FIG. 2 can be simplified by omitting the pickup circuit of the resonator 12.

In operation, the resonators will be driven so that their respective pole assemblies operate along the sinuous rims in the manner illustrated in FIG. 2A. Corresponding arms 11a and 12a of the two resonators will be driven so that the former is at its extremes of motion or excursion at the peaks and valleys of the sinuous rim a (in the planes indicated by the numerals 17 and 18), while the corresponding poles of the resonator 12 are disposed at the points of maximum slope of the sinuous rim 1012 (on the planee indicated by the line 16). It will also be noted that the adjacent arms 11b and 11c in adjacent quadrants move in opposite directions.

As a result, the motor is self-starting and will always turn in the same direction, the circuitry being designed to complement these characteristics. Also, at any given instant, at least one of the resonators will be imparting energy to the rotor through all of its poles disposed about the circumference of the rotor. At all other instants, both resonators to some extent will be driving the rotor at all pole points around the circumference and the forces will substantially balance at all times. The driving force results from a slight phase lead by the resonators with respect to the sinuous track. The magnitude of the lead is small and is designed to carry the specified load on the system. Departure from synchronism is typically caused by external forces, such as changes in the load on the motor or environmental effects such as shock, angular acceleration or the like. In the event the rotor starts to break away from synchronous speed downward, the lead of the resonators will increase to increase the component of magnetic attraction to increase driving force to correct the loss. The stored energy in the vibrating resonator will be drawn upon, as will the capacity of the circuit to impart additional energy to the rotor. In the case of overspeed, the rotor will first come into a position of complete alignment of the poles l5 and the track so that effectively the rotor de-couples and extracts no further torque from the driving resonators. In the event this does not correct the overspeed, the resonators will begin to lag the rotor and will impose a load on it, which is to say it will extract energy from the rotor. This will be stored in the resonator and the circuit will compensate as required. Thus, the motor is highly resistant to loss of synchronism without a requirement for fundamental overpowering or wasted power during normal operation.

The illustrated embodiment in which the sinuous rims are narrow at their points of maximum slope (where they correspond closely in size to the facing areas of the magnetic poles l5) and are thickened or distorted at their peaks and valleys, accommodates changes in amplitude of the resonators without imposing forces on the resonator arms perpendicular to their planes which would change their timekeeping ability.

Referring now to FIG. 3, a modification of the invention is disclosed in which like parts are identified by like primed reference numerals. In this arrangement, the resonator 11' is driven by its own pickup and drive circuit, indicated generally by the numeral 51, and the resonator 12' operates as a passive or slaved resonator driven from the rotor. As such, it is capable of feeding stored energy back to the rotor, or extracting energy from the rotor, as required to maintain synchronism. The sinuous rim 10b is of uniform thickness throughout because change in amplitude of the resonator does not normally occur and maximum coupling at all times is useful in the transfer of energy back and forth between the slaved resonator and the rotor. The characteristics of the sinuous rim drive are such that, in the event the rotor by either infinitesimal increases or decreases in speed tries to depart from synchronism with the resonator, a time or phase displacement in the sine wave traced by the poles 15' will occur with respect to the sinuous rims 10a and 10b and energy will be transferred as dictated by the requirement to maintain synchronism.

The motor of FIG. 3 is bidirectional in its operation and is not self-starting. A slight push in the desired direction can be imparted by any one of many known devices. The drive circuit can take a wide range of forms, including that disclosed in the applicants U.S. Pat. No. 3,150,337.

Referring to FIGS. 4 and 5, the invention is illustrated as embodied in a motor in which a rotor 52 is formed with a single sinuous strip rim 52a undulating in a direction perpendicular to the plane of the rotor, i.e. in the direction of its axis, and engaged by a composite resonator including eight arms 53a 4: extending from a common nodal center 54. These arms operate in coordinated unison in groups of four, with the arms 53a, c, e, and g forming one resonator and the anns 53b, d, f, and h forming the other resonator. This resonator can be formed from a single plate or it can be an assembly of two cruciform plates united in the area of the central node 54.

The arms 53a-h carry magnets 55a h respectively at their ends which work in conjunction with frame-mounted coils 56a h. Also carried by the arms 53a -h inside the mounting point for the magnets 55 are magnetic pole assemblies 57a -h respectively. The pole assemblies 57 are substantially identical, each comprising a plurality of radially spaced poles defining an arcuate channel which receives the sinuous rim 52a, and each pair of opposed poles carries opposed pole tips similar to the pole tips 15 shown in FIG. 2, which have a crosssectional dimension corresponding approximately to the width of the sinuous rim.

The pole assemblies of adjacent coordinate arms, such as the arms 53a and 530 are shifted circumferentially 180 along one sine wave pattern of the rim similar to the positioning of the pole assemblies for the resonator ll of Figures 1 and 2. The pole assemblies 57b and d and pole assemblies f and h of the second set of coordinate resonator arms are similarly spaced apart with the poles 57b and d being shifted 180 along the sine wave track, as are poles 57f and h. In addition, all of the poles 57b, d, f and h are shifted an additional relative to the poles 57a, 0, e and g.

The two resonators are operated 90 out of phase by appropriately energizing the respective coils 56a h and, to this end, circuitry similar to that disclosed in FIG. 1 or in FIG. 2 can be used (the latter being illustrated). It will be understood that various combinations of driving and pickup coils can be used and that to excite each resonator composed of four arms, only one pickup and one drive coil need by used. This drive coil can be disposed as a common coil on one arm or, if desired, a single common pickup and driving coil for all eight arms can be used in the form of one large winding having a diameter approximately equal to the diameter of the resonator assembly, although this configuration results in some loss of efficiency of the electromagnetic coupling to each arm. In operation, the arms will all vibrate in a coordinated fashion which duplicates precisely in function the arrangement described above in connection with FIGS. 1 and 2.

Referring to FIG. 6, an eight-armed resonator and rotor as sembly is shown which duplicates the function of the motor of FIG. 3, with four of the arms 580 d being coupled to the drive and pickup coils 590 -d respectively, as well as to the sinuous rim 60a of the rotor 60. The other four arms 61a d are coupled to the rim 60a and do not include drive or pickup coils. Thus, the arms 61a -d comprise a passive or slaved resonator similar to the resonator 12' of FIG. 3, and the overall action of the motor of FIG. 6 duplicates that of FIG. 3.

Various modifications can be made in the embodiments described herein within the scope of the invention. For example, referring to the arrangements of FIGS. 1, 2, and 3, it is possible to utilize a single sinuous strip rim on the rotors in place of two, by mounting the pole assemblies of the resonators on the far side from the rim on suitable axial extensions to the arms and turning them upside down to nest over the rim. When a common rim is used, it is required that the frequency of the two resonators by substantially equal, whereas the use of separate rims requires only that the frequencies of the resonators and the rim patterns be suitably coordinated. In such case, either one resonator should be passive or independent oscillator circuits should be used. Also, the sinuous rims can be made active magnetically, preferably using ceramic materials, and polarizing the rim north and south across its relatively thin wall. In such case, the pole assemblies on the resonator arms can be made of non-permanently magnetizable material, or both components can be magnetized. Also, while the sinuous rim has been illustrated as being continuous, it will be understood that it can also take the form of a series of all magnetic portions, the pattern of which essentially defines a sinusoidal track.

Furthermore, the pole assemblies and the sinuous track are essentially bidirectional so that, if desired, the sinuous track can be placed in the arcuate sections carried on the resonator arms to reciprocate therewith, and the rotor can carry the discrete poles circumferentially disposed about its axis of rotation. Either or both can be permanently magnetized. Because the sinuous rim and the discrete poles are interchangeable, it should also be understood that the rotor can perform the dual functions of resonator as well as rotor by mounting the rotor elements, 10, 10' or 52 on a fixed axis and allowing the resonators ll, 12, 12 or 53 to rotate. This necessitates a resonator drive other than individual coils receiving reciprocating magnets, and can be accomplished, as stated above, by providing a large common coil entirely surrounding the resonators. The invention should not, therefore, be regarded as limited except as defined in the appended claims.

Iclaim:

1. A timing motor comprising rotor and stator parts, one of the parts comprising a resonator having a plurality of coordinately and concomitantly vibratable portions which vibrate axially with respect to the axis of rotation of the rotor, a pair of complementary magnetically coupled members carried respectively by the other of the motor parts and the plurality of vibratable portions of the resonator, one of said members comprising a substantially sinuous magnetic track concentric with the axis of rotation of the rotor part and undulating in a direction parallel to the axis of rotation, and the other member comprising a plurality of magnetic pole means coupled respectively to the track at circumferentially spaced points in at least two different quadrants whereby under vibratory resonant motion of the resonator and rotation of the rotor part the members remain substantially fully magnetically coupled at all times, and drive means to excite the resonator into vibration to induce rotary motion of the rotor part through the magnetic couplings.

2. A timing motor according to claim 1, said magnetic pole means embracing the magnetic track radially to couple both sides thereof simultaneously to eliminate axial stress in the vibratable portion.

3. A timing motor according to claim 2, said plurality of concomitantly vibratable portions of the resonator having a common central node coaxial with the rotor.

4. A timing motor according to claim 3, said resonator comprising a plate member having at least four vibratable arms which vibrate out of the plane of the plate.

5. A timing motor in accordance with claim 4, each of the four arms of the plate carrying an arcuate magnetic head, with the four heads engaging the rotor in each of its four quadrants.

6. A timing motor according to claim 5, each of said heads having a plurality of poles to engage the sinuous track at a plurality of corresponding and circumferentially spaced points.

7. A timing motor according to claim 3, said resonator comprising at least eight arms extending radially outwardly from the axis of the rotor.

8. A timing motor according to claim 7, said eight anns being part of a common plate.

9. A timing motor comprising rotor and stator parts, one of said parts including a pair of electromechanical resonators having substantially the same resonant frequencies of vibration, means coupling each of the resonators magnetically to the other part with each coupling comprising a pair of complementary magnetically coupled members carried respectively by the stator and a resonator, one member comprising a substantially sinuous magnetic track means coaxial with the axis of rotation, and the other member comprising a pole assembly magnetically coupled to the track, and means to excite at least one of the resonators into resonance to impart rotation to the rotor through the magnetic coupling.

10. Apparatus according to claim 9, said second resonator being passive and thereby capable through phase lead-lag characteristics with respect to the sinuous path of both taking energy from and feeding energy back to the rotor to impart accelerating and decelerating forces to assist in maintaining synchronism of the rotor with the driven resonator.

11. Apparatus according to claim 9, including first and second drive means to excite the respective resonators into vibration, the magnetic coupling of the respective resonators being shifted with respect to the sinuous track, and said drive means for the respective resonators being 90 out of phase, whereby the rotor is self-starting in a predetermined direction upon excitation of the resonators.

12. Apparatus according to claim 9, both of said resonators including at least four arms extending from a common integrated central node coaxial with the rotor.

13. Apparatus according to claim 9, said sinuous track means comprising a single track for both resonators.

14. Apparatus as set forth in claim 9, said sinuous track means comprising two coaxial tracks for the respective resonators.

15. Apparatus according to claim 9, one of said resonators being driven and the other being passive.

16. Apparatus according to claim 9, said sinuous track means undulating in a direction parallel to the axis of rotation of the rotor.

17. Apparatus as set forth in claim 9, said drive means to excite the resonator including separate electromagnetic drives for each vibratable portion, whereby the energy to drive the rotor couples substantially directly from the electromagnetic drive means to the rotor.

18. Apparatus according to claim 11, said resonator having substantially the same frequency, said drive means for the resonator including pickup and drive circuit oscillator means for each resonator and 90 phase lock means connected between the two circuit means to maintain the 90 phase shift.

19. Apparatus according to claim 11, said resonators having substantially the same frequency, pickup means associated with one of the resonators, amplifier means to receive the pickup signal and connected to drive one of the resonators from which the pickup signals are derived, and second amplifier means including a 90 phase shifter for driving the other resonator. 

1. A timing motor comprising rotor and stator parts, one of the parts comprising a resonator having a plurality of coordinately and concomitantly vibratable portions which vibrate axially with respect to the axis of rotation of the rotor, a pair of complementary magnetically coupled members carried respectively by the other of the motor parts and the plurality of vibratable portions of the resonator, one of said members comprising a substantially sinuous magnetic track concentric with the axis of rotation of the rotor part and undulating in a direction parallel to the axis of rotation, and the other member comprising a plurality of magnetic pole means coupled respectively to the track at circumferentially spaced points in at least two different quadrants whereby under vibratory resonant motion of the resonator and rotation of the rotor part the members remain substantially fully magnetically coupled at all times, and drive means to excite the resonator into vibration to induce rotary motion of the rotor part through the magnetic couplings.
 2. A timing motor according to claim 1, said magnetic pole means embracing the magnetic track radially to couple both sides thereof simultaneously to eliminate axial stress in the vibratable portion.
 3. A timing motor according to claim 2, said plurality of concomitantly vibratable portions of the resonator having a common central node coaxial with the rotor.
 4. A timing motor according to claim 3, said resonator comprising a plate member having at least four vibratable arms which vibrate out of the plane of the plate.
 5. A timing motor in accordance with claim 4, each of the four arms of the plate carrying an arcuate magnetic head, with the four heads engaging the rotor in each of its four quadrants.
 6. A timing motor according to claim 5, each of said heads having a plurality of poles to engage the sinuous track at a plurality of corresponding and circumferentially spaced points.
 7. A timing motor according to claim 3, said resonator comprising at least eight arms extending radially outwardly from the axis of the rotor.
 8. A timing motor according to claim 7, said eight arms being part of a common plate.
 9. A timing motor comprising rotor and stator parts, one of said parts including a pair of electromechanical resonators having substantially the same resonant frequencies of vibration, means coupling each of the resonators magnetically to the other part with each coupling cOmprising a pair of complementary magnetically coupled members carried respectively by the stator and a resonator, one member comprising a substantially sinuous magnetic track means coaxial with the axis of rotation, and the other member comprising a pole assembly magnetically coupled to the track, and means to excite at least one of the resonators into resonance to impart rotation to the rotor through the magnetic coupling.
 10. Apparatus according to claim 9, said second resonator being passive and thereby capable through phase lead-lag characteristics with respect to the sinuous path of both taking energy from and feeding energy back to the rotor to impart accelerating and decelerating forces to assist in maintaining synchronism of the rotor with the driven resonator.
 11. Apparatus according to claim 9, including first and second drive means to excite the respective resonators into vibration, the magnetic coupling of the respective resonators being shifted 90* with respect to the sinuous track, and said drive means for the respective resonators being 90* out of phase, whereby the rotor is self-starting in a predetermined direction upon excitation of the resonators.
 12. Apparatus according to claim 9, both of said resonators including at least four arms extending from a common integrated central node coaxial with the rotor.
 13. Apparatus according to claim 9, said sinuous track means comprising a single track for both resonators.
 14. Apparatus as set forth in claim 9, said sinuous track means comprising two coaxial tracks for the respective resonators.
 15. Apparatus according to claim 9, one of said resonators being driven and the other being passive.
 16. Apparatus according to claim 9, said sinuous track means undulating in a direction parallel to the axis of rotation of the rotor.
 17. Apparatus as set forth in claim 9, said drive means to excite the resonator including separate electromagnetic drives for each vibratable portion, whereby the energy to drive the rotor couples substantially directly from the electromagnetic drive means to the rotor.
 18. Apparatus according to claim 11, said resonator having substantially the same frequency, said drive means for the resonator including pickup and drive circuit oscillator means for each resonator and 90* phase lock means connected between the two circuit means to maintain the 90* phase shift.
 19. Apparatus according to claim 11, said resonators having substantially the same frequency, pickup means associated with one of the resonators, amplifier means to receive the pickup signal and connected to drive one of the resonators from which the pickup signals are derived, and second amplifier means including a 90* phase shifter for driving the other resonator. 